Constructing Reality : Quantum Theory and Particle Physics

Questions Of The Fundamental Nature Of Matter Continue To Inspire And Engage Our Imagination. However, The Exciting New Concepts Of Strings, Supersymmetry And Exotic Matter Build On Ideas That Are Well Known To Physicists But Mysterious And Puzzling To People Outside Of These Research Fields. Covering Key Conceptual Developments From The Last Century, This Book Provides A Background To The Bold Ideas And Challenges Faced By Physicists Today. Quantum Theory And The Standard Model Of Particles Are Explained With Minimal Mathematics, And Advanced Topics, Such As Gauge Theory And Quantum Field Theory, Are Put Into Context. With Concise, Lucid Explanations, This Book Is An Essential Guide To The World Of Particle Physics-- This Picture Of The Winding State Vector Glosses Over The Subtlety That We Freely Choose When As Well As Where Or What To Measure. The Dirac View Separates The Abstract State Vector From All Of These Contingent Choices. Moreover, The Principles Of Relativity Demand That We Treat When And Where (time And Space) On A More Or Less Equal Footing. Thus A Better Choice For An Omniscient Picture Corresponding To The Classical 'tapestry Of World Lines' Is A Master State Vector For All Of Nature In An Abstract Hilbert Space 'outside Of Space And Time' Whose Coordinates Bear Labels For Time As Well As For Distance Or Momentum And Other Properties. In This Picture Space-time, Being A Property Of The Detectors, Not The Underlying Stuff, Is A Macroscopic Phenomenon. For Historical Reasons, The Picture In Which The State Vector Depends On Time Is Called The Schrodinger Picture, And The Alternative Static Case Is Called The Heisenberg Picture-- 1. The Nature Of Things -- 2. Matter And Motion In Space And Time -- 3. Reality Large And Small -- 4. The Language Of Nature -- 5. More Is Different -- 6. The Machinery Of Particle Discovery -- 7. The Standard Model -- 8. The Proliferation Of Matter -- Epilogue: Beneath Reality -- Appendix: How Quantum Mechanics Is Used. John Marburger. Includes Bibliographical References (p. [275]-281) And Index. Contents......Page 6 1 The nature of things......Page 10 1.1 NATURE DOES NOT CONFORM TO OUR EXPECTATIONS......Page 12 1.2 EXPLANATION VERSUS DESCRIPTION......Page 14 1.3 PHYSICISTS KEEP TRYING TO EXPLAIN THE “UNEXPLAINED”......Page 15 NOTES......Page 16 2.1 BERNHARD RIEMANN SPECULATES ON THE EMPIRICAL NATURE OF GEOMETRY......Page 20 2.2 THE WORK OF PHYSICS......Page 22 2.3 NEWTON’S UNVISUALIZABLE DESCRIPTION OF NATURE’S ACTION......Page 26 2.4 MAXWELL ADDS FIELDS TO THE LIST OF THINGS THAT ARE......Page 28 2.5 MAXWELL’S IMPACT (1): THE INVARIANT SPEED OF LIGHT......Page 30 2.6 EINSTEIN EXPOSES PREJUDICES ABOUT SPACE AND TIME......Page 32 2.7 A DIGRESSION ON E = MC2......Page 34 2.8 MINKOWSKI STRETCHES A NEW CANVAS FOR THE DEPICTION OF NATURE......Page 36 2.9 THE EVOLVING UNIVERSE AS A TAPESTRY OF WORLD-LINES IN SPACE-TIME......Page 38 2.10 EINSTEIN SAYS THE LAWS OF MOTION MUST NOT DEPEND UPON OURSELVES......Page 40 2.11 A NEW WAY OF THINKING ABOUT THE LAWS OF MOTION......Page 42 2.12 AN “EXPLANATION” FOR GRAVITY......Page 43 2.13 WEYL’S ATTEMPT TO EXPLAIN ELECTROMAGNETISM......Page 46 2.14 REFLECTIONS ON RIEMANN’S IDEA OF GEOMETRY AS PHYSICS......Page 49 NOTES......Page 50 3.1 DIGRESSION ON THE QUALITY OF KNOWLEDGE IN A UNIVERSE OF ATOMS......Page 61 3.2 MAXWELL’S IMPACT (2): THE MISMATCH BETWEEN PARTICLES AND FIELDS......Page 65 3.3 PLANCK POSTULATES A RELATION BETWEEN ENERGY AND FREQUENCY......Page 66 3.4 THE MATTER WAVE OF DE BROGLIE AND SCHRÖDINGER......Page 71 3.5 MEANWHILE, BACK IN COPENHAGEN . . .......Page 72 3.6 MAX BORN’S STATISTICAL INTERPRETATION......Page 73 3.7 THE QUANTUM MICROSCOPIC WORLD VIEW: STEP 1......Page 76 3.8 SCHRÖDINGER’S CAT......Page 79 3.9 WAVES VERSUS PARTICLES......Page 83 3.10 ABOUT WAVES......Page 84 3.11 THE “UNCERTAINTY PRINCIPLE”......Page 88 3.12 AMPLITUDES AND PHASES......Page 91 3.13 QUANTUM PHASE AS A NEW “DIMENSION” OF NATURE, AND WEYL’S TRIUMPH......Page 94 3.14 ELECTROMAGNETISM “EXPLAINED”......Page 98 NOTES......Page 100 4.1 MATHEMATICAL THINGS......Page 111 4.2 SCHRÖDINGER’S WAVE AS A SET OF VECTOR COMPONENTS......Page 117 4.3 THE QUANTUM STATE VECTOR IS NOT OF THIS WORLD......Page 121 4.4 A NEW PERSPECTIVE ON UNCERTAINTY AND COMPLEMENTARITY......Page 123 4.5 MORE STRUCTURE FOR SCHRÖDINGER’S WAVE: “INTRINSIC SPIN”......Page 126 4.6 SPIN IS NOT ENOUGH......Page 130 4.7 THE POSITRON INTRUDES......Page 131 4.8 ANTI-MATTER......Page 133 NOTES......Page 135 5.1 THE QUANTUM MICROSCOPIC WORLD VIEW: STEP 2......Page 141 5.2 SYSTEMS WITH MULTIPLE EXCITATIONS......Page 142 5.3 QUANTUM FIELD THEORY......Page 144 5.4 GUESSING EQUATIONS OF MOTION......Page 146 5.5 “STATISTICS”......Page 148 5.6 ABOUT DETECTORS......Page 152 5.7 THE DISTURBING ARGUMENT OF EINSTEIN, PODOLSKY, AND ROSEN (EPR)......Page 153 5.8 BELL’S INEQUALITY......Page 157 5.9 THE ENTANGLED UNIVERSE......Page 160 NOTES......Page 161 6 The machinery of particle discovery......Page 166 6.1 MAXWELL’S IMPACT (3): ATOMISM UNDERMINED......Page 167 6.2 PARTICLE SPECTROSCOPY......Page 170 6.3 THE BIG MACHINES......Page 172 6.4 NEUTRONS AND NEUTRINOS......Page 174 6.5 MORE INTERNAL “DIMENSIONS”? ISOSPIN......Page 175 6.6 MESONS AND THE RANGE OF FORCES......Page 178 6.7 IF ISOSPIN WERE “REAL”......Page 180 6.8 SYMMETRIES (1): CONSERVATION LAWS......Page 183 6.9 SYMMETRIES (2): GROUPS......Page 186 6.10 SYMMETRIES (3): GROUP REPRESENTATIONS......Page 190 6.11 THE GAME OF PARTICLE DISCOVERY......Page 192 6.12 UNITARITY AND RENORMALIZATION......Page 193 6.13 SPONTANEOUS SYMMETRY BREAKING......Page 196 NOTES......Page 199 7 The Standard Model......Page 206 7.1 LEPTONS......Page 209 7.2 QUARKS......Page 212 7.3 FORCES......Page 218 7.4 ELECTROMAGNETISM AND QED......Page 219 7.5 THE STRONG FORCE AND QCD......Page 223 7.6 THE WEAK FORCE (BUT NO QWD)......Page 230 7.7 ELECTRO-WEAK UNIFICATION......Page 233 7.8 PARITY VIOLATION......Page 235 7.9 CP VIOLATION......Page 236 7.11 A DIGRESSION ON SUPERCONDUCTIVITY......Page 238 7.12 THE HIGGS MECHANISM......Page 240 7.13 THE HIGGS BOSON(S)......Page 243 NOTES......Page 245 8.1 AN ABBREVIATED HISTORY OF CREATION......Page 257 8.2 NUCLEONS AND NUCLEI......Page 261 8.3 THE PERIODIC TABLE OF ELEMENTS......Page 264 NOTES......Page 268 Epilogue: Beneath reality......Page 271 Appendix: How quantum mechanics is used......Page 275 NOTES......Page 282 References......Page 284 Index......Page 291 "This picture of the winding state vector glosses over the subtlety that we freely choose when as well as where or what to measure. The Dirac view separates the abstract state vector from all of these contingent choices. Moreover, the principles of relativity demand that we treat when and where (time and space) on a more or less equal footing. Thus a better choice for an omniscient picture corresponding to the classical 'tapestry of world lines' is a Master State Vector for all of nature in an abstract Hilbert space 'outside of space and time' whose coordinates bear labels for time as well as for distance or momentum and other properties. In this picture space-time, being a property of the detectors, not the underlying stuff, is a macroscopic phenomenon. For historical reasons, the picture in which the state vector depends on time is called the Schrodinger picture, and the alternative static case is called the Heisenberg picture"-- Provided by publisher Machine generated contents note: 1. The nature of things; 2. Matter and motion in space and time; 3. Reality large and small; 4. The language of nature; 5. More is different; 6. The machinery of particle discovery; 7. The Standard Model; 8. The proliferation of matter; 9. Epilogue: beneath reality; Appendix; References; Index.